The airing of a Russian-produced documentary series on Soviet leaders by Czech public television violated broadcasting regulations, the Central European country's media regulator has said.

The eight-part series, Forgotten Leaders, which aired on Czech Television (CT) in December, included a two-part segment on Lavrenty Beria, the notorious former Soviet secret police chief.

The Czech Council for Radio and Television Broadcasting said that the series "highlighted Beria's 'managerial' successes and character," while minimizing or ignoring his role in Soviet dictator Josef Stalin's reign of terror, the Czech news portal Lidovky.cz reported on January 19.

The state media regulator's actions come amid concerns that the Kremlin is increasing its propaganda efforts in the Czech Republic, especially as President Milos Zeman seeks reelection.

Zeman has divided the nation of 10.5 million with his pro-Russian stance and his support for closer ties with China. He has also become known for strong antimigrant rhetoric.

Zeman has also called for referendums on Czech membership in the EU and NATO, although he himself favors remaining in both.

The 73-year-old Zeman faces a runoff against the pro-European Jiri Drahos on January 26-27.

The media regulator called on CT to correct its errors, although it was unclear how the public broadcaster might do this, especially since the documentary has already been aired.

The chairman of the regulator, Ivan Krejci, said it was more of a warning not to repeat the same mistake in the future.

A 2016 Czech study concluded that Russian propaganda efforts in the Czech Republic are aimed at sowing distrust and disbelief in Europe and its institutions.

In the wake of the conflict in Ukraine, Russian operations in the Czech Republic have intensified, the Czech Security Service said in 2017. Russia has repeatedly denied accusations that it meddles in domestic affairs, including elections, in the United States and Europe.

The Czech Republic has set up the Center Against Terrorism and Hybrid Threats, an Interior Ministry unit tasked with combating risks ranging from terrorism and radicalization to state propaganda.